|Debate over Euro continues in UK|
The prime minister told Sky News that he relished the challenge of taking on hostile public opinion.
"This is a fundamental question for this country - do we want to be part of the main strategic alliance right on our doorstep - Europe?
"Do we really want to be partners, play our full part in it, make sure that it is shaped in the British national interest, or do we want to be marginalised and left without influence?" he asked.
Asked if he would call for a referendum even if he knew he would lose, Blair said he believed he could convert public opinion.
"It's going to be a big battle there's no doubt about that," he said. "But I think with the British people they will also listen to a considered argument in a much more deep way than people sometimes think."
Polls show most Britons want to keep the sterling. But Blair has promised a vote if he decides to go for euro entry.
"There is no point being in politics unless you are prepared to take on the big issues," he said.
However, Blair cautioned that Britain should only switch currencies if the economics were conducive.
His pro-euro interview came on the heels of a Russia-European Union summit, and after a new poll suggests more than half of all Britons believe Britain should quit the European Union rather than accept a new constitution that transfers powers from London to Brussels.
According to a YouGov poll published in the Mail on Sunday, 51% of Britons said withdrawal from the EU was preferable to the "surrender" of further powers to Brussels.
That was against 29% who said Britain should accept a loss of power in order to stay in the union.
|Many Britons are unwilling to give|
up the sterling pound for the Euro
The survey also suggested 75% of voters wanted a referendum on the draft constitution.
The Conservative party has repeatedly called for a referendum.
But Blair has rejected the idea of a referendum, accusing those demanding one of secretly wanting total British withdrawal from the EU.
But on Sunday, former Italian prime minister, Lamberto Dini, warned the UK public of being misled over the draft constitution for the European Union.
He told the Sunday Telegraph that the constitution will "change people’s lives."
"Anyone in Britain who claims the constitution will not change things is trying to sweeten the pill for those who don't want to see a bigger role for Europe."
"Eventually the union will be able to make legislation of its own. It will become an institution and organisation in its own right."
Blair has often stated the euro to be part of Britain's destiny, but after six years in government he has failed to confront the issue. The UK remains one of only three "euro outs" in the 15-member bloc.
Blair said his cabinet of top ministers are to meet on Thursday to make a final decision on whether to recommend ditching the pound. However, he admitted that they had not yet reached a collective position.